The study design was changed.

The efficacy of the current standard triple therapy is at an unacceptably low level. Resistance to antibiotics is suspected to be the major cause of the low efficacy of standard triple therapy. Point mutations in the 23S rRNA gene are known to be the primary mechanism of clarithromycin resistance against H pylori. Recently, a point mutation detection kit using a dual-priming oligonucleotide (DPO)-based multiplex polymerase chain reaction (PCR) assay was introduced and made commercially available. The primary goal of our study was to compare the eradication rates of empirical therapy and tailored therapy. Specifically we examined the eradication rates of 7-d, 14-d empirical therapy with 7-d, 14-d tailored therapy. Our secondary goal was to examine the adverse events of each treatment, cost effectiveness of each treatment methods, and accuracy of DPO-PCR for detecting H. pylori resistance.

Patients are randomly assigned to the empirical therapy group and tailored therapy group.

The empirical therapy group recieves triple therapy of 7 or 14 days. The tailored therapy group receives treatment based on their DPO-PCR results.

Patients who are sensitive to clarithromycin based on DPO-PCR receives triple therapy for 7 or 14 days. Patients who are resistant to clarithromycin based on DPO-PCR recieves bismuth quadruple therapy for 7 or 14 days.

Inclusion Criteria:

• consecutive subjects who underwent upper gastrointestinal endoscopy and who had a confirmed diagnosis of H pylori infection

Exclusion Criteria:

• subjects younger than 18 years old
• subjects with a history of H pylori eradication
• subjects who had previous gastric surgery
• subjects who were pregnant or lactating
• subjects with serious concurrent illness
• subjects who were administered antibiotics, bismuth, or PPIs in the 8 weeks preceding the study
• subjects with a history of allergy to any one of the compounds in this study